The Spanish authorities have ordered an operation to seal holes in the hull of the sunken tanker Prestige, from which oil has been leaking towards Spain's Atlantic coast.

The job will be done using a French submarine which last week managed to plug a crack in the ship.

One of the Prestige's holes has been successfully sealed

A Spanish government scientific committee has now recommended that the remaining 13 holes should be patched, to prevent thousands more tons of oil from escaping.

The announcement came as a third slick from the Prestige reached the shores of north-west Spain on Wednesday.

Fresh patches of oil have been found along parts of the Galician coastline where earlier slicks had hit.

Month-long job

But Spanish officials hope that attempts to seal the leaking wreck on the seabed might be successful.

The French mini-submarine Nautile last week stopped one leak from the ship - which is spilling about 125 metric tons of oil per day.

The Nautile is expected to start plugging the other holes on Thursday. Officials say the work is expected to take about a month.

Spanish PM Jose Maria Aznar got a hostile reception in Galicia

The ageing, single-hulled tanker broke in two and sank last month, and is so far estimated to have lost about a quarter of its cargo of heavy fuel oil.

The Spanish Government has faced strong criticism for its handling of the crisis, including the decision to tow the stricken tanker further out to sea before it sank.

The move was designed to protect the coastline, but meant the ship finally sank in 3,500 metres (12,000 feet) of water, turning attempts to deal with the massive quantity of oil still on board into a technical nightmare.

Spanish Prime Minister Jose Maria Aznar has accepted that mistakes may have been made.

Fishermen's misery

The scale of the cost so far was revealed
by Treasury Minister Cristobal Montoro.

"To date we have spent around 200 million euros... a significant amount, which will be topped up with European funds soon," said Mr Montoro.

We are in a desperate situation

Pablo VillarHunger striker

The areas hit by the disaster are expected to receive 265 million euros of EU funding.

The stretch of coastline affected by Wednesday's oil was between Corme in the north to Ribeira in the south - the same area hit by two earlier slicks.

Some fishermen have gone on hunger strike to demand a bigger operation be mounted against the slicks, which would involve the Spanish navy trying to keep the oil at sea.

"We are in a desperate situation," said Pablo Villar, the head of a fisheries association at Cangas in the Ria de Vigo, told Spanish radio.

Ria de Vigo is one of the many local estuaries which are home to one of Europe's biggest fishing fleets.

Crown Prince Felipe has received a warmer reception

Fishermen have been using home-made booms to try to protect some of their valuable shellfish beds.

Government officials say it has been hard to deploy pumping vessels because of the choppy seas and strong winds.

An estimated 20,000 metric tons of the original 77,000-ton cargo is now thought to have escaped.

Crown Prince Felipe, the son of King Juan Carlos, who has been touring Galicia, described the Prestige as a "bomb on the seabed".

He has been receiving a much warmer reception than Mr Aznar, who was met by angry protesters when he made his first visit to the region.